Cut 500 grams of raw jackfruit into small pieces and boil them in water with a pinch of salt for 10-15 minutes, until they become tender. Drain the water and let the jackfruit pieces cool down.
In a pan, heat 100 ml of mustard oil until it reaches its smoking point. Turn off the heat and let it cool down to room temperature.
In a separate pan, dry roast 2 tablespoons of mustard seeds, 1 tablespoon of fenugreek seeds, and 1 tablespoon of fennel seeds until they become fragrant. Grind them into a coarse powder using a mixer grinder.
In the cooled mustard oil, add 1 tablespoon of asafoetida (hing), the ground spice powder, 2 tablespoons of red chili powder, 1 tablespoon of turmeric powder, and salt to taste. Mix well to form a thick paste.
Add the boiled and cooled jackfruit pieces to the spice paste and mix well, ensuring that each piece is coated evenly with the spices.
Transfer the jackfruit pickle to a clean, dry, and sterilized glass jar. Seal the jar tightly and let it sit in a cool, dark place for 3-4 days to allow the flavors to develop.
After 3-4 days, the jackfruit pickle is ready to be served. Store it in the refrigerator to extend its shelf life.